they call them falling stars, yeah? how big is a falling star on the average? humungous, humungous, humungous or humungous, humungous, humungous, humungous or about the size of a grain of sand. take your pick, gang. hint, last one. grain of sand, 15, 20 miles up and these things... even if they're standing still with respect to the sun, here comes the earth, thousands of miles an hour. and that grain of sand burns up in the air. and you look up, hey, wow, a star, honey. it ain't no star. it's a grain of sand, looks like-- if you lit a match up there, it'd look like a star and it's just a grain of sand burning up by friction, going so fast. and so when the space shuttle comes in, one of the big problems of the space shuttle when they first got this thing, how are you gonna get that thing back down into the air? you kinda go out gradual, gradual, gradual, but when you come back in, you're gonna come in with a splash, so they have to make it so it will melt, but the part that melts is not the part where the people's feet are, okay?